From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=DKIM_INVALID,DKIM_SIGNED, MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 14036 invoked from network); 1 Dec 2021 14:02:07 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 1 Dec 2021 14:02:07 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 819AE9CF1E; Thu, 2 Dec 2021 00:02:02 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 0773C9C78B; Thu, 2 Dec 2021 00:01:16 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=planet.nl header.i=@planet.nl header.b="bLuYDLOP"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id C92EC9C78B; Wed, 1 Dec 2021 23:59:58 +1000 (AEST) Received: from ewsoutbound.kpnmail.nl (ewsoutbound.kpnmail.nl [195.121.94.168]) by minnie.tuhs.org (Postfix) with ESMTPS id 24B9794502 for ; Wed, 1 Dec 2021 23:59:52 +1000 (AEST) X-KPN-MessageId: e2bea110-52ae-11ec-8862-005056aba152 Received: from smtp.kpnmail.nl (unknown [10.31.155.38]) by ewsoutbound.so.kpn.org (Halon) with ESMTPS id e2bea110-52ae-11ec-8862-005056aba152; Wed, 01 Dec 2021 14:59:22 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=planet.nl; s=planet01; h=to:date:message-id:subject:mime-version:content-type:from; bh=lqpzyMkMKfzFszsy3VTPf484m7e/sdwj5LQcFH4/2HU=; b=bLuYDLOPftconO/cfBSNuTRC9nLED5sy6L7uZ8azvILae/zcOWX31HPvD/q8CWxgq51Sq2KBN0oz4 ByyOURlLrD4lijhcwmYdRn8k15mkdoLew0eO/GpFUB/JMNa7lX/ycjidFYGnuofOBZS997sVs9BENJ 3P1HIlG9GXz6MHic= X-KPN-MID: 33|0j/h6BOROKTk/VYPEmCv0yShr07KI4jH5LJ5VOp+fhE6CoAjzJnJiQdhkWNscGS 9NBrKvXyh859f5Xm2k2b8TZ2CA7/Itd6JqBjCvCXRmvU= X-KPN-VerifiedSender: Yes X-CMASSUN: 33|GfwBXnz7ErIw2RyCxH7hOA/ymskOjz42Og60RXo//DXV1B670nQlpjuvtR2yrVd mYavpt6LAXfwEhJMpqk8LCQ== X-Originating-IP: 80.101.112.122 Received: from mba2.fritz.box (sqlite.xs4all.nl [80.101.112.122]) by smtp.kpnmail.nl (Halon) with ESMTPSA id f0e417ea-52ae-11ec-94d2-005056abf0db; Wed, 01 Dec 2021 14:59:46 +0100 (CET) From: Paul Ruizendaal Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 13.4 \(3608.120.23.2.4\)) Message-Id: <219A3DE7-3DA1-4618-82B2-9354D63F93DF@planet.nl> Date: Wed, 1 Dec 2021 14:59:45 +0100 To: TUHS main list X-Mailer: Apple Mail (2.3608.120.23.2.4) Subject: [TUHS] Encoding an ISA: Random Logic vs. Control Stores X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" For DEC memo=E2=80=99s on designing the PDP-11 see bitsavers: http://www.bitsavers.org/pdf/dec/pdp11/memos/ (thank you Bitsavers! I love that archive) Ad van de Goor (author of a few of the memo=E2=80=99s) was my MSc thesis = professor. I recall him saying in the early 80=E2=80=99s that in his = view the PDP-11 should have been an 18-bit machine; he reasoned that = even in the late 60=E2=80=99s it was obvious that 16-bits of address = space was not enough for the lifespan of the design. --- For those who want to experiment with FPGA=E2=80=99s and ancient = ISA=E2=80=99s, here is my plain Verilog code for the TI 9995 chip, which = has an instruction set that is highly reminiscent of the PDP-11: https://gitlab.com/pnru/cortex/-/tree/master The actual CPU code (TMS99095.v) is less than 1000 lines of code. Paul